如何在NSLog中打印布尔标志?
有没有办法在NSLog中打印布尔标志的值?
以下是我如何做到的:
BOOL flag = YES; NSLog(flag ? @"Yes" : @"No");
?:
是表单的三元条件运算符:
condition ? result_if_true : result_if_false
在适当的地方相应replace实际的日志string
%d
, 0为FALSE, 1为TRUE。
BOOL b; NSLog(@"Bool value: %d",b);
要么
NSLog(@"bool %s", b ? "true" : "false");
根据数据types%@
变化如下
For Strings you use %@ For int you use %i For float and double you use %f
布尔只不过是整数,它们只是types铸造值…
typedef signed char BOOL; #define YES (BOOL)1 #define NO (BOOL)0 BOOL value = YES; NSLog(@"Bool value: %d",value);
如果输出是1,否则是否
请注意,在Swift中,你可以做
let testBool: Bool = true NSLog("testBool = %@", testBool.description)
这将loggingtestBool = true
虽然这不是对Devang的问题的直接回答,但我相信下面的macros可以帮助那些希望loggingBOOL的人。 这将注销bool的值,并自动用variables名称标注它。
#define LogBool(BOOLVARIABLE) NSLog(@"%s: %@",#BOOLVARIABLE, BOOLVARIABLE ? @"YES" : @"NO" ) BOOL success = NO; LogBool(success); // Prints out 'success: NO' to the console success = YES; LogBool(success); // Prints out 'success: YES' to the console
苹果的FixIt提供了%hhd,这正确地给了我BOOL的价值。
我们可以通过四种方式来检查
第一种方法是
BOOL flagWayOne = TRUE; NSLog(@"The flagWayOne result is - %@",flagWayOne ? @"TRUE":@"FALSE");
第二种方法是
BOOL flagWayTwo = YES; NSLog(@"The flagWayTwo result is - %@",flagWayTwo ? @"YES":@"NO");
第三种方法是
BOOL flagWayThree = 1; NSLog(@"The flagWayThree result is - %d",flagWayThree ? 1:0);
第四种方法是
BOOL flagWayFour = FALSE; // You can set YES or NO here.Because TRUE = YES,FALSE = NO and also 1 is equal to YES,TRUE and 0 is equal to FALSE,NO whatever you want set here. NSLog(@"The flagWayFour result is - %s",flagWayFour ? YES:NO);
NSArray *array1 = [NSArray arrayWithObjects:@"todd1", @"todd2", @"todd3", nil]; bool objectMembership = [array1 containsObject:@"todd1"]; NSLog(@"%d",objectMembership); // prints 1 or 0
这里是你如何做到这一点:
BOOL flag = NO; NSLog(flag ? @"YES" : @"NO");
//assuming b is BOOL. ternary operator helps us in any language. NSLog(@"result is :%@",((b==YES)?@"YES":@"NO"));